This invention relates to an expansion pipe for use with an engine.
In a number of countries small two stroke or four stroke gasoline (petrol) engines are subject to strict exhaust gas emission control standards, a requirement which is generally met by the original manufacturer fitting catalytic converters to the engines.
If this type of engine is used to power a small vehicle such as a scooter or cart then it is quite common for a user, or vehicle manufacturer, to attempt to increase the power output of the engine by adding a performance enhancing system to the engine. Typically use is made of an expansion pipe which is connected to an exhaust port of the engine. When this is done however it is no longer possible for the modified engine to meet exhaust gas emission requirements.
The invention is concerned with a performance enhancing system which can be used with an engine to which a catalytic converter or similar device is fitted, without affecting the exhaust gas emission rating of the engine.